The National Highway Traffic and Safety Administration (NHTSA) is opening a query on Ford’s response to a recall last year that affected almost 49,000 Mustang Mach-E vehicles, as reported by Automotive News. The June 2022 recall was issued due to a malfunction involving overheating of the electric SUV’s high-voltage contactors, which, at worst, can make the EV suddenly lose power on the road, increasing the risk of a crash.

Occurances would often follow high-speed battery charging or repeated fast acceleration sessions.

Ford issued an over-the-air (OTA) software update to respond to the recall, which was designed to reduce power if the contactors got too hot — in hopes of preventing sudden power loss and possible damage to the contacts. The automaker also held new Mach-E deliveries at dealerships until they received the software update. The automaker had additionally opened a service bulletin to replace the High Voltage Battery Junction Box in affected vehicles.

Now, NHTSA’s Office of Defects Investigation reports receiving 12 consumer complaints regarding Ford’s solution.

The Office of Defects Investigation (ODI) has opened this Recall Query (RQ) after receiving 12 consumer complaints alleging a high voltage battery main contactor failure in MY 2021-2022 Ford Mach-E vehicles (subject vehicles) that were included in Recall 22V-412 and remedied prior to the reported incidents. The remedy in this recall was a Secondary On-Board Diagnostic Control Module (SOBDMC) software update to monitor contactor temperature and reduce battery power to prevent damage to the contactor, and a Battery Energy Control Module (BECM) software update to monitor contactor resistance to identify an overheated contactor and reduce vehicle power to prevent further damage.

One customer complaint dated August 19th says they had to get the High Voltage Battery Junction Box replaced twice for the same electrical system issue. Another complaint in February mentioned the failure reoccurred after getting the software update.

The original recall affected 48,924 2021 and 2022 Mustang Mach-E vehicles built between May 27th, 2020, and May 24th, 2022, at Ford’s Cuautitlan plant in Mexico. For the new query, NHTSA says an estimated 64,727 vehicles are part of its investigation.